Northern Kentucky University

Poster Title

Syntheses of Polystyrene-Organoclay Nanocomposites using Thiol-Functionalized Organoclays

Institution

Northern Kentucky University

Abstract

Organoclay-polymer nanocomposites are a class of hybrid materials that are composed of an organic polymer matrix that has inorganic clay nanofillers dispersed within. The incorporation of inorganic fillers into polymeric matrices is a process that has been used for years to improve polymer properties. These nanocomposites exhibit enhanced mechanical, thermal and gas impermeability properties. However, in order to produce a material with desirable properties, complete dispersion (or exfoliation) of the inorganic clay layers within the polymer matrix is necessary. In this project, we investigated the syntheses of polystyrene-organoclay nanocomposites using an organoclay containing a thiol (SH) group (Mg-MTMS) combined with polystyrene (PS). Nanocomposites were prepared using two processes: 1) A solution process where various amounts (1, 5, 10, 25 wt%) of thiol-functionalized organoclay is dispersed into a polymer solution. 2) A surface-initiated polymerization method where the polymerization of the polystyrene takes place after reaction of the styrene monomers with the thiol groups of the organoclay layers acting as anchoring sites for the polymer chains. The optical transparency of the nanocomposite films prepared using the first method was determined and we found that: i) the higher the organoclay content, the lower the transparency of the film and ii) a mechanical stirring of the organoclay/polystyrene mixture is the best dispersion method to maintain a high level of transparency of the films even at high organoclay content. For the nanocomposites prepared with the second method, we were able to obtain evidence of the thiol group reaction with the styrene monomers and consequently, grafting of the polystyrene onto the layers by infrared spectroscopy.

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Syntheses of Polystyrene-Organoclay Nanocomposites using Thiol-Functionalized Organoclays

Organoclay-polymer nanocomposites are a class of hybrid materials that are composed of an organic polymer matrix that has inorganic clay nanofillers dispersed within. The incorporation of inorganic fillers into polymeric matrices is a process that has been used for years to improve polymer properties. These nanocomposites exhibit enhanced mechanical, thermal and gas impermeability properties. However, in order to produce a material with desirable properties, complete dispersion (or exfoliation) of the inorganic clay layers within the polymer matrix is necessary. In this project, we investigated the syntheses of polystyrene-organoclay nanocomposites using an organoclay containing a thiol (SH) group (Mg-MTMS) combined with polystyrene (PS). Nanocomposites were prepared using two processes: 1) A solution process where various amounts (1, 5, 10, 25 wt%) of thiol-functionalized organoclay is dispersed into a polymer solution. 2) A surface-initiated polymerization method where the polymerization of the polystyrene takes place after reaction of the styrene monomers with the thiol groups of the organoclay layers acting as anchoring sites for the polymer chains. The optical transparency of the nanocomposite films prepared using the first method was determined and we found that: i) the higher the organoclay content, the lower the transparency of the film and ii) a mechanical stirring of the organoclay/polystyrene mixture is the best dispersion method to maintain a high level of transparency of the films even at high organoclay content. For the nanocomposites prepared with the second method, we were able to obtain evidence of the thiol group reaction with the styrene monomers and consequently, grafting of the polystyrene onto the layers by infrared spectroscopy.